Fair Value Measurement (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 26,725	$ 2,765	$ 38,510	$ 22,320
Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3			60,000
Other Contract [Member] | Other Nonoperating Income (Expense) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	27,175	4,432	39,464	26,836
Other Contract [Member] | RLJE [Member] | Other Nonoperating Income (Expense) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 20,600	$ 2,000	$ 30,200	$ 19,100
Measurement Input, Discount for Lack of Marketability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount for Lack of Marketability (Deprecated 2018-01-31)	0.32		0.32